To enhance competition, many manufacturing companies seek to simplify various aspects of their businesses through automation. This is particularly true for those concerned with bulk manufacturing such as injection-molded manufacturing, where each step of production may yield a number of articles. Often, the rate at which such articles can be produced is limited only by how fast these articles can be removed, collected or dispersed. In view of this challenge, automators have concentrated on fewer steps and more reliable methods. The present invention has succeeded in accomplishing both for the orientation of predominately flat articles such as lids, closures and the like.
While the automated process for orientating objects such as lids goes back to at least the early 1970's, many of the devices of the prior art which claim to orient actually work by an accept/reject technique. This is clearly illustrated by U.S. Pat. No. 3599829 to Aidlin, et al., and U.S. Pat. No. 4093062 to Sjogren. Both of these inventions separate properly oriented articles from improperly oriented articles by forcing the latter back into a holding bin or such. These improperly oriented articles are rejected in hope that they will correctly orient in their fall. In a rapid production process this could potentially cause an undesirable backup or at least add steps to the process.
A second technique used in the art is the indiscriminate flipping of articles. This is best illustrated by U.S. Pat. No. 3734268 to Burger, et al. and U.S. Pat. No. 4709798 to Herzog. Burger supplies a constant air flow sufficient to flip upside down lids, while those correctly oriented deflect the air flow. Obviously, the strength of the indiscriminate air flow is very important, ensuring only improperly oriented lids are flipped. The Herzog invention employs essentially the same process for flipping the articles, but also combines the accept/reject technique. After the articles are flipped (or not) a sensor determines if any are still improperly oriented, triggering a blast of air to blow them back into a rotating bowl. Again, random processes are employed in hopes that proper orientation will occur. This indiscriminate process is also undesirable for some article designs where the continuous air may flip such articles irrespective of their immediate orientation.
A further consideration, in view of the Burger and Herzog patents, is the force which must be exerted upon each article. In such designs air flow must be great enough to overcome the weight of the article, while at the same time be small enough to have no effect on properly oriented articles. Thus, narrow margins can be presented.
Other designs, which are not necessarily relevant to the present invention but employ re-orientation methods, include U.S. Pat. No. 4907686 to Cotic, U.S. Pat. No. 4799613 to Adamson, U.S. Pat. No. 3874740 to Hurd, and U.S. Pat. No. 3334729 to Kosrow. The Cotic device is unique and distinctly different from the present invention in that it is intended for flipping railroad tie plates which can weigh anywhere from 18-40 pounds each. This is clearly not a question of scale--lids weigh only a few grams--but involves problems completely different than those encountered by those skilled in the field to which the present invention pertains. Cotic employs hydraulic cylinders to exert force from below the plates. This applied force must be greater than the mass of the plate (ie., greater than 18 to 40 pounds) to accomplish the re-orientation. This would require a substantial air jet, which would probably be impractical if not impossible to generate.
Both the Adamson and Kosrow inventions relate to orienting cloth, or clothing garments. Again, the problems encountered in trying to flip flimsy articles is very different from those in the field to which the present invention relates. Obviously, due to the porous nature of cloth material, and the lack of sturdiness of entire garments, air would be an inappropriate and ineffective medium for re-orienting these articles.
Finally, with respect to Hurd, the device and method taught is very specific to the cap-shaped article shown. If little or no physical difference exist between top side and bottom side of the article, as is common for many lid and closure designs, the disclosed invention is incapable of re-orientation of the article. Further, if it is desirable to have all the cap-shaped articles oriented with the open side upward the Hurd device is incapable of such orientation.
The present invention, in both its apparatus designs and methods, recognizes and addresses these concerns and overcomes the limitations perceived by those skilled in the art by presenting a design which, among other aspects, allows for the flipping of either only improperly oriented articles through selective application of a force on those articles, or flipping of all articles by continuous application of a force. Particularly, the present invention allows utilization of a force less in magnitude than the weight of the article to correctly orient flat articles quickly and reliably. Other designs which attempt to orient flat articles merely reject those which are improperly oriented, or indiscriminately apply a force in an effort to flip no more and no less than those improperly oriented. The prior art demonstrates the substantial attempts made by those skilled in the art to fill the need for a quality orientor. Instead of understanding the true problem, manufacturers have coped with the inherent limitation to some of these devices and methods, apparently, all because there was a failure to fully understand the problems of properly orienting articles such as lids, and the like.